WASHINGTON, United States (AFP) — The Kamala Harris campaign said Friday it raised $310 million in July — more than double her US presidential rival Donald Trump — with the vast bulk of new cash pouring in after she replaced Joe Biden as the Democratic Party nominee.

Harris’s campaign appears to have energised large and small donors alike — a turnaround from the uncertain period after a disastrous Biden debate performance, when major donors reportedly halted fundraising.

The $310 million sum, which the Harris campaign said was the biggest haul of the 2024 cycle, includes more than $200 million in donations in the week following Biden’s endorsement of his vice president as his replacement.

The sum reflects funds raised across the campaign, the Democratic National Committee and joint fundraising committees, the statement said, and came from more than three million donors.

Two-thirds of the money was sent in by first-time donors, the campaign said, calling the haul the best grassroots fundraising month in presidential history.

During the same month, Trump’s campaign said it raised $138.7 million, in a press release Thursday.

That brings the former Republican president’s cash on hand to $327 million, while Harris’s war chest now stands at $377 million.

Trump’s White House bid was thrown into chaos on July 21 when Biden withdrew his candidacy, backing Harris as the Democratic nominee.

“The tremendous outpouring of support we’ve seen in just a short time makes clear the Harris coalition is mobilised, growing and ready to put in the work to defeat Trump this November,” said campaign manager Julie Chavez Rodriguez.

Harris has seen her favourability ratings jump as she has reeled in Trump, who sparked a firestorm of outrage after he claimed falsely on Wednesday that she had decided to “turn Black” for political gain.

Compared with June, when Biden was still the nominee, the number of Gen Z donors increased by more than 10 times, while the number of millennial donors increased by more than eight times.

Meanwhile coalition groups such as Black Women for Harris, Latinas for Harris and even one called White Dudes for Harris raised more than $20 million, the campaign said.